In standard 802.11 for wireless local area network, an access point (AP) and multiple stations (STA) associated with the AP constitute a basic service set (BSS).
In practical application, multiple BSS operating on the same channel commonly have overlapping coverage areas, thereby forming an overlapping BSS (OBSS). In the OBSS, multiple APs send data on the same channel, or multiple STAs send data on the same channel, which may result in damage of a data frame. In the prior art, in order to reduce frequency interference generated when the APs or STAs send data on the same channel in the OBSS, a method for adjusting a bandwidth dynamically is provided in the 802.11 standard to eliminate the interference. The AP sends a request to send (RTS) frame on multiple sub-channels, the STA feeds back a clear To send (CTS) frame on a sub-channel with small interference, a maximum bandwidth available for communication is labeled in the CTS frame, and thus the AP adjusts a channel bandwidth for data communication with the STA based on the CTS frame.
With the existing method for adjusting the bandwidth dynamically, in a case that the APs send data, each of multiple STAs in an OBSS interference area may feed back the CTS frame to the AP associated therewith on the same sub-channel with small interference, since the multiple STAs suffer similar level of interference. Thus, the APs may obtain the same channel after performing the dynamic bandwidth adjustment based on the CTS frame; and great same-frequency interference may be generated when the APs send data to the STA associated therewith on the same channel.